时间轴相互转换

将时间转换成秒

    -(NSString *) getSecondsWithTime:(NSString *)time
    {
        NSDateFormatter *formatter = [[NSDateFormatter alloc]init];
        [formatter setDateFormat:@"YYYY-MM-dd HH:mm:ss"];
        NSDate *date = [formatter dateFromString:time];
        NSString *timeStr = [NSString stringWithFormat:@"%ld",(long)[date timeIntervalSince1970]];
        
        return timeStr;
    }

将秒转换成时间

-(NSString *) getTimeWithSeconds:(NSString *)seconds
{
    NSInteger time=[seconds longLongValue];
    NSDate *d = [[NSDate alloc]initWithTimeIntervalSince1970:time];
    NSDateFormatter *formatter = [[NSDateFormatter alloc]init];
    [formatter setDateFormat:@"yyyy-MM-dd HH:mm:ss"];
    NSString*timeString=[formatter stringFromDate:d];
    return timeString;
}